The landscape for treating pediatric achondroplasia (the most common genetic form of short-limbed skeletal dysplasia) has evolved in ways that bring new challenges for endocrinologists and other clinicians. A first-ever treatment, Voxzogo (vosoritide), was approved by the Food and Drug Administration in 2023 to increase growth in patients with achondroplasia at birth.
Historically, patients with achondroplasia were seen by geneticists for diagnosis and routine management – and by surgeons for treatment at different ages. Endocrinologists typically encounter a patient with achondroplasia only once or twice in their careers.
Vosoritide has changed that, creating a greater need for familiarity with this rare disease and its care throughout childhood, according to Nadia Merchant, M.D., Pediatric Endocrinologist at Children’s Health℠ and Associate Professor of Pediatrics at UT Southwestern.
An expert in achondroplasia, Dr. Merchant collaborated on international consensus guidelines for vosoritide therapy and more recently, published related advice and common clinical scenarios for endocrinologists in The Journal of Clinical Endocrinology & Metabolism.
In this Q&A, Dr. Merchant shares how endocrinologists can manage achondroplasia care.
“There is an urgent need to provide practical guidance to endocrinologists about the diagnosis, management and surveillance of these patients,” she says.
Why did you want to share achondroplasia care recommendations with other endocrinologists?
My co-authors and I felt educating endocrinologists on a condition they never trained for was important. If endocrinologists are prescribing vosoritide, they need to be comfortable with the complexities of achondroplasia care and the routine management of these patients. Also, the international vosoritide guidelines are great, but we know there are challenges in applying them. Our paper offers advice on how you take care of a kid depending on your location and what age group you're seeing.
What are the potential benefits of vosoritide?
The data has shown that it improves growth, at an average rate of 1.57 centimeters annually. There are great and not-so-great responders, but in general, the more years you treat a child with vosoritide, the more growth you're going to get.
We don't know yet whether it's improving foramen magnum stenosis, spinal stenosis or any of the other achondroplasia complications. We want to see more data from ongoing studies, and we're hoping that as time goes on, we’ll see improvement besides growth.
What should endocrinologists know about achondroplasia?
Achondroplasia is an autosomal dominant condition, so if somebody has achondroplasia, they have a 50% chance of passing it down. But 80% of patients with this condition are born to average-height parents, so families are not necessarily going to see this coming.
Between having non-invasive prenatal testing for achondroplasia available and treatment available at birth, we are seeing more patients at a younger age.
There is an increased risk of sudden death in the first year of life due to central sleep apnea and foramen magnum stenosis that cannot be ignored. These patients will immediately need MRIs and sleep studies. For those, refer the patient to your regional skeletal dysplasia center; most have developed surveillance protocols for infants to ensure they’re seen quickly.
Routine management is very important. Depending on the age of the child, there are different recommendations for routine care.
How can endocrinologists prepare for seeing patients with achondroplasia?
You should be comfortable and familiar with the AAP health supervision guidance for these patients published in 2020. This report doesn’t discuss vosoritide because it wasn't yet approved, so be sure to also read the international consensus guidelines to understand the appropriate management of vosoritide.
How do you advise families about vosoritide?
We share how vosoritide is an option. Some families may say, “We don't want to do daily injections starting at birth for a few inches of growth” while others may say, “Yes, we definitely want this.” Also, it's not a “if I start, I must continue” scenario. It's OK for families to decide to start the medication for a while, and if they feel their child is not benefiting or if the child doesn't want it anymore, they can always stop. And if the kid's old enough, this should be done as shared decision-making. There are also different drugs in the pipeline – including a weekly injection and a daily pill – so there might be other options available in the future and the option to enroll in current clinical trials.
Why Children’s Health: Expert achondroplasia care
Children's Health sees a high volume of patients with achondroplasia, and our endocrinologists and geneticists collaborate closely with experts in neurosurgery, otolaryngology, orthopedics, sleep medicine and maternal fetal medicine. We also lead innovative achondroplasia research and serve as a clinical trial site for multiple skeletal disorder medications. This gives us the experience and expertise to create a multidisciplinary care plan that matches each patient's needs and gives them the best opportunity for a good outcome.
Learn more about our multidisciplinary achondroplasia care at Children's Health.
